The present invention relates in general to so-called "ring" brakes, that is to say brakes whose rotating brake member comprises an axially-extending cylindrical drum or ring having braking surfaces formed respectively on the inner and outer surfaces of the ring. Such brakes are also known as "internal-external shoe drum brakes". A brake of this kind comprises a fixed support designed to be secured to some suitable support member, for example a wheel axle, on the shaft of which is mounted the corresponding ring, two brake pads arranged on both sides of this ring, and control means adapted to act on the said brake pads so as to apply the latter to both sides of the said ring in a direction that is overall radial to this ring, termed hereinafter the pressure or clamping axis, and which passes through the central region of each of the brake pads.
The present invention relates more particularly to the case where the fixed support comprises two side members arranged on both sides of an axial plane of the brake containing the pressure axis, and adapted to retain circumferentially the brake pads during braking.
In practice, both brake pads are at least partially enclosed by the side members of the fixed support, or by other elements of the latter integral with said side members, in such a way that, during braking and because of the fact that they tend to be subjected to a circumferential force when they are applied to the brake ring, they both circumferentially contact that one of the said side members which, in the direction of rotation of the said ring, is "downstream" hereinafter termed the "down" side member.
Thus, such a down side member is usually the only one which is subject to the braking force.
In order to subject also the "upstream" side member of the fixed support to the braking force, it has been proposed to couple circumferentially the two side members, i.e. the up and down side members of the fixed support, by one or a plurality of connecting bars.
With connecting bars situated within the ring, these are usually radially disposed at a distance from the regions of the side members of the fixed support against which the circumferential ends of the brake pad can come into contact which, also being located within the interior of the ring, is associated with the internal face of the latter. There is thus a radial displacement between the region of a side member involved in absorbing the braking force due to such an internal pad, and the region of the same side member by which the latter is, for reinforcement purposes, coupled to the other member by the connecting bar.
The object of the present invention is generally a ring-type brake of the type briefly described above, in which measures are adopted to provide a better adaptation of the connecting bar circumferentially coupling the side members of the fixed support in the interior of the ring, to the forces that the said connecting bar has to transmit.